NAME
intrbald — daemon for balancing interrupts
SYNOPSIS
/usr/sbin/intrbald
[-i
interval |
-k | -c]
DESCRIPTION
Balancing interrupts is a process which distributes interrupts
across the available CPUs in an optimal fashion.
This action
is performed by
intctl(1M).
Performing frequent CPU migrations between system partitions may
require you to perform periodic balancing of interrupts.
This is especially true with systems that use WLM (Workload Manager),
iCAP (Instant Capacity), and vPARs (Virtual Partions) products.
If the frequency of CPU migration is high then balancing of
interrupts should be performed more frequently.
The
intrbald
daemon monitors the system for imbalance in interrupt distribution.
If an imbalance is detected, after the specified interval
(INTRBALD_INTERVAL),
intrbald
executes
intctl -b
to balance the interrupt distribution.
intctl
uses the parameters from the
/etc/intctl.conf
configuration file for balancing the interrupts.
For more information about the
intctl
command, see
intctl(1M)
and the
/etc/intctl.conf
configuration file.
The
intrbald
daemon is started from the general purpose sequencer
rc
script (see
rc(1M)),
/sbin/init.d/intrbald_init,
at run level 2 and is killed at run level 1.
By default, it is not enabled.
The daemon configuration file
/etc/rc.config.d/intrbaldconf
must be edited and the parameter
INTRBALD_STATE
set to
enabled
in order to enable running the daemon.
After setting
INTRBALD_STATE
to
enabled
for the first time, you can start the daemon
manually by executing the
rc
script
(/sbin/init.d/intrbald_init start).
Otherwise, the daemon will automatically start the next time the system
is restarted.
Any actions performed by the daemon are logged in
syslog
and details of interrupt migrations performed will be logged in
the file
/var/adm/intrbald.log.
Options
- -c
Instruct the running daemon to reexamine the configuration file
/etc/rc.config.d/intrbaldconf.
If the
INTRBALD_INTERVAL
parameter has been updated, then the running daemon uses the
new value.
If the
INTRBALD_STATE
parameter is set to
disabled,
then the running daemon stops executing.
- -i interval
The daemon checks if the system requires any balancing of interrupts
after
interval
seconds; valid range is 5 seconds to
INT_MAX
seconds (see
limits(5)).
This value can also be specified persistently in the configuration file
/etc/rc.config.d/intrbaldconf
by setting the
INTRBALD_INTERVAL
parameter.
The default value is 60 seconds.
Setting this value too small can cause unnecessary interrupt migrations.
- -k
Gracefully kills the running daemon.
intrbald rc Configuration File
/etc/rc.config.d/intrbaldconf
is the
intrbald rc
configuration file.
The following parameters can be persistently specified in this
configuration file:
- INTRBALD_STATE
Specifies if the daemon should be started automatically during
the system bootup process by the
rc
script.
The daemon will only be started automatically if this parameter is set to
enabled.
NOTE: This value is
disabled
by default.
Before using the daemon,
the value needs to be changed to
enabled
in the
/etc/rc.config.d/intrbaldconf
file.
Then the daemon needs to
be started, either manually by running
intrbald,
or it will be started automatically at next boot via the
rc
script.
- INTRBALD_INTERVAL
The daemon will check if the system requires any
interrupt balancing after this interval.
Interval is specified in seconds; valid range is 5 seconds to
INT_MAX
seconds (see
limits(5)).
The default is 60 seconds.
Setting this value too small could cause unnecessary
interrupt migrations.
RETURN VALUE
Exit values are:
- 0
Successful completion.
- >0
An error condition occurred.
WARNINGS
The
intrbald
command can be executed only by the superuser.
This command should be used only by performance analysts for
performance tuning purposes.
If care is not taken to redistribute the interrupts properly, it could
lead to a decrease in the overall system performance by overloading
some processors and by not optimally utilizing the remaining processors.
FILES
- /etc/rc.config.d/intrbaldconf
intrbald rc
configuration file.
See the
intrbald rc Configuration File
section above.
- /sbin/init.d/intrbald_init
intrbald rc
script.
- /sbin/rc2.d/S900intrbald_init
rc
start symbolic link.
- /sbin/rc1.d/K100intrbald_init
rc
kill symbolic link.
- /var/adm/intrbald.log
daemon log file.
